What is the recommended treatment for bullous impetigo?

Treatment of Bullous Impetigo

For bullous impetigo, the recommended treatment is topical mupirocin or retapamulin applied twice daily for 5 days as first-line therapy for limited disease, while oral antibiotics active against Staphylococcus aureus are recommended for extensive disease. 1

Causative Organism

• Bullous impetigo is caused exclusively by Staphylococcus aureus strains that produce toxins cleaving the dermal-epidermal junction, forming fragile, thin-roofed vesicopustules 1, 2
• These lesions may rupture, creating crusted, erythematous erosions often surrounded by remnants of the blister roof 1, 3

Treatment Algorithm

For Limited Disease:

• Topical antibiotics are first-line therapy 1, 4:
  • Mupirocin 2% ointment applied twice daily for 5 days 1, 4
  • Retapamulin applied twice daily for 5 days 1
• Clinical efficacy rates for mupirocin are significantly higher than placebo (71% vs 35%) 4
• Topical therapy has fewer side effects than oral antibiotics 5

For Extensive Disease or Multiple Lesions:

• Oral antibiotics for 7 days are recommended 6, 1
• For methicillin-susceptible S. aureus (MSSA):
  • Dicloxacillin or cephalexin are first-line options 6, 1
• For suspected or confirmed MRSA:
  • Doxycycline, clindamycin, or sulfamethoxazole-trimethoprim (SMX-TMP) 6, 1
• Oral penicillin V is not recommended as it is seldom effective against S. aureus 7

Special Considerations

• Oral antibiotics should also be considered during outbreaks affecting several people to decrease transmission 1
• Topical disinfectants are inferior to antibiotics and should not be used 2, 5
• Monitor for clinical response within 24-48 hours when using oral antibiotics 1
• If progression occurs despite antibiotics, consider:
  • Infection with resistant organisms 1, 2
  • Presence of a deeper infection than initially recognized 1

Efficacy Comparisons

• Topical mupirocin has been shown to be slightly superior to oral erythromycin in multiple studies (RR 1.07,95% CI 1.01 to 1.13) 5
• Mupirocin and fusidic acid have similar efficacy rates 5
• Topical antibiotics are significantly better than disinfecting treatments (RR 1.15,95% CI 1.01 to 1.32) 5

Antibiotic Resistance Considerations

• Worldwide, bacteria causing impetigo show growing resistance rates for commonly used antibiotics 5
• For suspected MRSA infections, clindamycin is helpful 2
• SMX-TMP covers MRSA but is inadequate for streptococcal infections 2

Bullous impetigo usually resolves within two to three weeks without scarring, and complications are rare, with the most serious being poststreptococcal glomerulonephritis 2.